#
# diskhits - disk access by file offset.
# Written using DTrace (Solaris 10 3/05).
#
# $Id: diskhits 3 2007-08-01 10:50:08Z brendan $
#
# This prints how a file was accessed, the locations on a distribution plot.
# This is for the cache misses only - the file activity that resulted in
# disk events.
#
# USAGE: diskhits pathname
# eg,
#
# FIELDS:
# Location (KB) The file offset of the disk activity, Kbytes.
# Size (KB) Size of the disk activity, Kbytes.
# Total RW Total disk activity, reads + writes.
#
# BASED ON: /usr/demo/dtrace/applicat.d
#
# SEE ALSO: DTrace Guide "io Provider" chapter (docs.oracle.com)
# iosnoop (DTraceToolkit)
#
# PORTIONS: Copyright (c) 2005, 2006 Brendan Gregg.
#
# CDDL HEADER START
#
# The contents of this file are subject to the terms of the
# Common Development and Distribution License, Version 1.0 only
# (the "License"). You may not use this file except in compliance
# with the License.
#
# See the License for the specific language governing permissions
# and limitations under the License.
#
# CDDL HEADER END
#
# 08-Jun-2005 Brendan Gregg Created this.
# 20-Apr-2006 " " Last update.
#
### Usage
function usage
{
cat <<-END >&2
USAGE: diskhits pathname
eg,
diskhits /var/adm/wtmpx
END
exit 1
}
### Process arguments
if (( $# != 1 )); then
usage
fi
if [[ $1 == "-h" ]]; then
usage
fi
pathname=$1
if [[ ! -e $pathname ]]; then
print "ERROR2: file $pathname not found" >&2
exit 2
fi
### Calculate output scale
report_lines=20
set -- `ls -l $pathname`
filesize=$5
(( file_kb_max = filesize / 1024 ))
(( scale_kb = filesize / (1024 * report_lines) ))
if (( file_kb_max < 20 )); then file_kb_max=20; fi
if (( scale_kb < 1 )); then scale_kb=1; fi
#
# Run DTrace
#
/usr/sbin/dtrace -n '
#pragma D option quiet
inline string PATHNAME = "'$pathname'";
inline int FILE_KB_MAX = '$file_kb_max';
inline int SCALE_KB = '$scale_kb';
dtrace:::BEGIN
{
printf("Tracing... Hit Ctrl-C to end.\n");
}
io:::start
/args[2]->fi_pathname == PATHNAME/
{
this->kb = args[2]->fi_offset == -1 ? -1 : args[2]->fi_offset / 1024;
@Location = lquantize(this->kb, 0, FILE_KB_MAX, SCALE_KB);
@Size = quantize(args[0]->b_bcount/1024);
@Total = sum(args[0]->b_bcount/1024);
}
dtrace:::END
{
printf("Location (KB),");
printa(@Location);
printf("Size (KB),");
printa(@Size);
printa("Total RW: %@d KB\n", @Total);
}
'